Temperature responsive control for fuel oil heaters



June 19, 1951 J, T. VOORHEIS 2,557,327

TEMPERATURE RESPONSIVE CONTROL FOR FUEL OIL HEATERS Filed Aug. 20, 1948 I N VEN TOR. ./ajfga Z" @arba/5 Patented June 19, V1951y UNITED STATES PATENT OF FICEl TEMPERATURE RESPONSIVE CONTROL FOR FUEL OIL HEATERS Joseph T; Voorheis, Piedmont, Calif., assigner to The Coen- Eompany, SanFrancsco, Calif., a cornnration. of California,

Application August20, 1948;,i Serial No. 45,369

30laims. l MyA invention relatesto means for use especially in heating,r fluids and particularly for use in heating oil which is subsequently to be burned as fuel. 'Such heaters are very often installedr in connection with burners usefull in the generation of 'steam or in otherlocations wherea steam supply isavailable. It often happens, however,l that the burners utilizing thev fuel oil must be started or maintained under circumstances during which timethere is not steam` available. Furthermore, if the amount of attention and regulation required for an oil heater is great, its usage may be uneconomical'. or even undesirable; It is considered, however, to be an advantageto heat fuel and as a matter of fact itv is necessary to heat some ofthe heavier` gradesof oil used as fuel.

It is therefore anl object ofE my invention to provide a fuel oil heater of' improved characteristics.

Another object of' my inventionI is to providea fuel oil heater which is substantially: automatic in its operation.

An additional object ofv the invention is to provid-e a fuel oil heater effective to heat fuel: with or without. an available supply of: steam.

An additional objectof the invention is to supply a fuel oil heater in which the transfer offheat to the fuel oil is extremelyf effective and eco:- nomical,

A stillV further object of the invention is to 3.

provide a, fuel oil heater readily manufactured of simple components and' which. can readily be attended to, if service is; necessary, by ordinary means and methods;

Other objects` together'with the, foregoing are attained in the embodiment or they invention illustrated in,the,accompanyingdrawing in which Figure 1 is a diagrammaticfshowing of a fuel oil heater installed in accordance withmy in.- Vention, the, heater itself being shown substantially, in side elevation.`

Figure 2 is a cross-section, the planesofr which are indicated by the lines 2-2 of Figurelr...

Figure 3. is a cross-section,y the .plane of which is indicatedY by the linea-3 of, Figure 2.

In its preferred form,.the .fue1; oil] heater oli-my invention comprises a. housing; in.l which a water level is automaticallymaintainedthewater beingy preferably derivedfromexternal steam and the interior of thehousing being, at ay temperature to support the presence of. steam at. a, Dredetermined pressure. 'Ihe amount of; liquid in the heater is automatically.controlled eitherV in accordance with the fuel, oil; temperature; orrwiththeincomingsteam. temperaturelor both. In the steam and water for the fuel oil heater.

l customary type, to a connector event the external steam is not readily available, an electric heater is supplied for heating the water to make steam internally, the heater itself being automatically controlled in accordance with the temperature of the issuing oil. The oil is` heated by passing through an oil conducting tube having convolutions within the housing in the steam space, and arranged so that oil circulatingI through it derives suilicient heat from the steam to cause condensation of part of the steam, the condensate supplying additional water to the housing.

While the fuel oil heater of my invention can readily be embodied in many diiierent forms and' its construction changed from time to time in accordance with specic installations, it has been successfully incorporated in the particular form shown and described herein. In this form there is provided a housing 6 including an outer tubular member 'l having heads 8l and 9 at the opposite ends thereof to provide a closed, pressuretight vessel. The vessel is mounted on suitable brackets II for support on any appropriate surface and is usually installed in a location wherein there is available a steam supply line I2. Steam from this supply line is utilized' to afford heating For'this; reason the steam line I2 is continued through a throttle valve I3 and a check valve I4, of the I6' in the upper side of the housing 6. Steam flowing into the housing condenses therein and forms a water deposit. While a drain plug I1 is afforded for cleaning and general overhaul purposes, normallyv it isA seated. Since there is no outlet for the water, it continues to rise inside of the housing 6 as condensate is added until such time at least. asit achieves a predetermined level indicated byv the-line I8 in Figures 2 and 3. The water level is. visible on the exterior of the housing through a water glass I9 and is maintained at that levelV by an overflow opening 2| connected through a valve 22 and a hand valve 23 to an overflow pipe 24" from which the water is discharged. When thel valves 22 and 23 are both open,l the water level; within the housing is maintainedv substantially at the' plane of the line I8. In the event the steam entering the chamber 6 comes in at a temperature too great completely to condense, thenthe pressure within the housing 6 is built up as shown by a conveniently attached gage 26. TheI pressure ofthe steam is restricted to a maximumamount byv a relief valve'2l ofthecustomary kindset to pop offV or blow at all pressures abovea pre-K determined pressure. A handle 28 is available amasar' temperature, the amount of steam required is reduced and vice versa. In this way the temtricity. The conductor 33 is grounded and the Y conductor 34 extends to a main control box 36.

That in turn is connected by a wire' 31 to a l transformer 3B joined to a terminal 39 extending to a source of power, the other side of the circuit being represented by a conductor 4| connected to ground. When the control box 36 permits current to flow, the heater 3| is energized and water within the housing 6 is converted into steam at the requisite pressure as set by the relief valve 21, Since the temperature of the steam corresponds tothe pressure thereof, there is likewise established a predetermined temperature within the housing 6.

- The heat within the housing, either furnished by the steam from the conductor l2 or the electric heater 3|,v is utilized to heat oil. Oil from any suitable source such as a pump 43 is forced through a pipe 44 into an inlet connection 46 to an oil conducting tube 41. This tube extends through the head 9 and is convoluted within the housing 6 above the water level I8 therein, that is, it is in the steam space of the housing, and eventually emerges through the head'9 to an outlet duct 48. The oil from the pump 43 consequently iiows completely through the housing and back out again. In order for theY oil to be Vin good heat exchanging relationship with the ambient steam and in order to provide a large heat exchange surface but to maintain a high oil iiow rate or velocity, the interior of the relatively large tube 41 is provided as shown in f rounding steam and causes condensation of such steam. The heat liberated by the condensation of the steam is manyV times that which would begiven up by a mere temperature dropin steam itself and hence a substantial transfer of heat from the steam to the oil is effectuated. This makes it possible to reduce very substantially the amount of surface required for the convoluted tube i1 and even so provides the desired temperature rise in the quantity of oil flowing therethrough. Condensate drops from the tube and hence does not hinder heat flow.

'Ihe heated cil discharged through the duct 48 passes through a temperature responsive device 54 connected hya transmission pipe 55 to a contrcller 51 for the valve I3. Since the valve is aA steam throttle, there is thus provided a mechanism for controlling the quantity of steam supplied to the heater in accordance with the temperature of the oil emerging therefrom. That is,Y ifV the .oil emerges at higher than desiredperature of the outgoing oil is carefully regulated.

In a similar fashion, in the event the steam supply is not available or in the event the electric heater is utilized in addition to the steam supply or in any case wherein the electric heater is utilized, the voutiiowing oil passing through the temperature responsive member V54 then travels through a second temperature responsive member 58 before coming to its outlet 59. The

vmember 58 controls an electrical switch 6| effective through the control box 36 upon the Vheater 3| so that when the oil temperature is too high, the heater is turned off and vice versa.

Thus either the steam quantity or the quantity of electric heat is made responsive to the temperature of the outgoing oil. Y

An additional control is provided for the'steam mechanism in that in the line |2 is disposed a temperature responsive element 62 eifective to govern a switch 63.between the main switch 36 and a solenoid 64 controlling the valve 22. The arrangement is such that while the hand valve 23 is normally open, the valve 22 is closed in the event no steam is flowing. When, however, the steam iiows through the line I2, the temperature of the responsive mechanism is increased, the switch 63 is closed, the solenoid 64 is energized and the valve 22 is open permitting a discharge of excess condensate through the overiow 2| so that the level I8 is always maintained.

In addition, and especially when the supply of heat comes from the heater 3| rather than steam from the line I2, there is provided an additional solenoid 66 effective upon the overflow valve 22 so that when the heater 3| is operating, the master control 36 not only energizes the heater 3| but also energizes the solenoid 66 and produces the same eiect upon Vthe valve 22 as does the solenoid 64. Depending upon the conditions of installation and operation from time to time there may be a water flow through the pipe: l2 instead of 'a steam flow. In any case, however, the flowing oil is heated by available steam either alone or supplemented by the electric heater 3| or a supply of water is heated by the electrical heater. Since steam condenses in thermal relationship with the oil flowing through the heater, higher temperature is imparted to it. Furthermore the steam supplying system and the electrical heating system can be utilized simultaneously or separately. The oil for fuel is readily heated by the condensation of steam and the size of the heater, the amount of heat transfer surface necessary,

and the general complexity of the mechanism Y are very much reduced over previous practice. Furthermore, the structure is all automatic in its operation' and functionsfor protracted periods under Widely varying'conditions to supply a substantially uniformly heated quantity Vof o il for combustion.

I claim: 1

1. A fuel oil heater comprising a housing. means for supplying water inthe form of steam to said housing,v a water drain at a predetermined level in said housing, a valve controlling .said drain', an oil conducting tube passing through said housing above said level, and means responsive tothe temperature Vof ilfiiwing through said tube for controlling said valve.

f 2. A fuel oil heater `comprising a housing. means for supplying water in the form of steam to said housing, a water drain at a predetermined level in said housing. a valve controlling 'said drain, an oil conducting tube passing through said housing in heat absorbing relationship with said steam therein, and means responsive to the temperature of steam in said supplying means for controlling said valve.

3. A fuel oil heater comprising a housing, means for supplying water in the form of steam to said housing, a water drain at a predetermined level in said housing, a valve controlling said drain, an oil conducting tube passing through said housing in heat absorbing relationship with said steam therein, means responsive to the ternperature of oil flowing through said tube for controlling said valve, and means responsive to the temperature of steam in said supplying means for controlling said valve.

JOSEPH T. VOORHEIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,723,082 Schumann Aug. 6, 1929 2,223,551 Carson Dec. 3, 1940 2,354,932 Walker et a1 Aug. 1, 1944 FOREIGN PATENTS Number Country Date 444,919 Germany May 27, 1927 

